An automatic control device of an infinitely variable transmission driven by an internal combustion engine, especially for a motor vehicle, wherein an accelerator travel signal is transmitted by an accelerator pedal for the purpose of, on the one hand, adjusting the throttle valve opening and, on the other, operating a servo-adjusting device by means of which the infinitely variable transmission gear is regulated is known, for example, from the publication DE-OS No. 27 12 327. This German Patent document describes a system whereby an accelerator pedal with subsequent accelerator pedal signal transmitter produces a signal that is used, via a first store or memory, to control the throttle-valve opening. In the first store a function F.sub.1 is so stored that the store transmits an output signal which serves as a measure for the opening angle of the butterfly valve of the carburettor. In addition, the accelerator output signal is transmitted to a second sotre or memory that holds a function F.sub.2. The second store provides an output signal corresponding to the calculated speed of rotation of the internal combustion engine. This second store in conjunction with a comparator circuit controls a servo-adjusting device for the direct operation of the infinitely variable transmission.
This circuit of an automatic control system of an infinitely variable transmission gear driven by an internal combustion engine is extremely cumbersome. It requires two memories to ensure, on the one hand, the control of the throttle valve opening and, on the other, the control of the infinitely variable gear unit. Furthermore, it entails the risk of failure if, as a result of incorrectly stored functions in the first and second stores, optimum adaptation cannot be achieved. In such a case there would be no optimum adaptation of the control process of the servo-adjusting device to the regulation of the opening angle of the butterfly valve. As a result, the fuel consumption would rise again.